German Patent Application DE 197 09 016 A1 describes a roof module, which is installed in a roof opening of the vehicle body during vehicle assembly, using an adhesive bonding process. To this end, the roof module is provided at its edge with a flange which extends all around and which, in the assembly position, overlaps an opening flange in the roof opening of the vehicle body and is joined thereto by adhesive beads. The roof module includes an outer shell formed from a metallic material, such as sheet steel, and an inner shell, which is formed from a foamed plastic and connected to the outer shell in sandwich fashion. The inner shell is provided with receiving grooves for adhesive molded into the foamed plastic in the region where the inner shell is supported on the opening flanges of the vehicle body. These receiving grooves prevent the adhesive from leaking out and are dimensioned so as to provide an adapted channel for the adhesive bead.
While in the case of the composite roof of German Patent Application DE 197 09 016 A1, an adapted adhesive channel may be provided by suitably shaping the plastic inner shell, this is generally not the case, especially when using glass roofs, roof opening systems, and roof modules made of certain metallic materials (such as sheet aluminum) because, in this case, molding-in of adhesive channels is not possible, economically not practicable, and not feasible with sufficient accuracy and reproducibility. In this case, therefore, the connection area between the roof module and the roof opening must be designed in an alternative manner, ensuring that the adhesive is arranged in the desired position and shape between the inner surface of the roof module and the upper surface of the opening flanges. In this instance, the roof module must be reproducibly connected to the flanges of the roof opening in such a way that, on the one hand, excessive squeezing of the adhesive bead and the associated risk of adhesive leakage are prevented. On the other hand, it must be ensured, with high process reliability, that the adhesive bead spans the gap between the inner surface of the roof module and the upper surface of the flanges, thus providing a sealing connection between the roof module and the roof opening.